<template>
  <transition :name="isNext? 'big': 'small'">
    <div class="swiper-item" v-show="show">
      <slot></slot>
    </div>
  </transition>
</template>

<script>
export default {
  data() {
    return {
    }
  },
  computed: {
    index() {
      return this.$parent.$children.findIndex(item => item === this)
    },
    show() {
      return this.index === this.$parent.currentSwiper
    },
    isNext() {
      return this.index < this.$parent.currentSwiper || (this.index === this.$parent.swipers.length - 1 && this.$parent.currentSwiper === 0)
    }
  },
  created() {
    this.$parent.swipers.push(this);
  }
}
</script>

<style lang="less" scoped>
.swiper-item {
  height: 100%;
  width: 100%;
  position: absolute;
  left: 0;
  top: 0;
  transform-origin: center center;
}
</style>

<style lang="less">
  &.big-enter-active, &.big-leave-active {
    transition: all 0.5s;
  }
  &.big-leave-active {
    z-index: 3;
    opacity: 0;
    transform: scale(1.3)
  }
  &.small-enter-active, &.small-leave-active {
    transition: all 0.5s;
  }
  &.small-leave-active {
    z-index: 3;
    opacity: 0;
    transform: scale(.8)
  }
</style>
